Method of cleaning internal-combustion engines and composition therefor



Patented Jan. 20, 1953 METHOD OF CLEANING INTERNAL-M- BUSTION ENGINES AND COMPOSITION THEREFOR Oliver L. Brandes, Gibsonia, and Charles B. Pattinson, Jr.,' Oakmont, Pa., assignor's to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware No Drawing. Application August 18, 1947, Serial No. 769,320

e ciaims. (01. 13440) This invention relates to a method of removing gum, lacquer, and carbonaceous deposits from internal combustion engines and to novel engine cleaning compositions used in connection therewith.

In the operation of an internal combustion engine the pistonrings, ring grooves, cylinder walls, oil lines, oil screen, bearings, and crankcase wall become coated with gum, lacquer, and carbonaceous deposits. These deposits result largely from incomplete combustion of fuel and oxidation of the mineral lubricating oil. If these deposits are allowed to accumulate, serious effects will develop such as the sticking of piston rings, the plugging of oil lines, and the excessive wear of bearing surfaces. The gum, lacquer, and carbonaceous deposits which are formed on the parts of an internal combustion engine may be removed by disassembling the engine, mechanically cleaning the respective parts, and then reassembling the engine. This method of cleaning, however, is laborious and expensive. Other methods of removing these deposits have involved the use of light mineral oils alone or in combination with various solvents. Light mineral oils, however, are not satisfactory solvents for the gum, lacquer, and carbonaceous deposits. Compositions in which a mineral oil is compounded with a solvent have met with some success; however, they contain mineral oil which acts as a diluent to the solvent, thus cutting down on the efliciency of these compositions. Still other engine cleaning compositions have been employed in which no mineral oil is present. These compositions, however, have not been entirely satisfactory in that they do not contain sufficient lubricating properties to insure safe operation of an engine during the cleansing period. 1

Among the objects achieved by this invention is the provision of a method of removing gum, lacquer, and carbonaceous deposits from an internal combustion engine by employing an improved engine cleaning composition.

Another object achieved by the present invention is the provision of new and improved engine cleaning compositions capable of removing gum, lacquer, and carbonaceous deposits from an internal combustion engine.

A further object achieved by this inventio is the provision of new and improved engine cleaning compositions having suflicient lubricating properties to insure safe operation of an engine during the cleansing period.

Other objects achieved by this invention will become apparent in the following detailed description thereof.

We have discovered that gum, lacquer, and carbonaceous deposits can be effectively removed from an internal combustion engine and at the same time maintain sufiicient lubrication to insure safe operation of an engine during the cleansing period by employing a solvent-detergent composition consisting of a homogeneous mixture of water, detergent, and organic solvents. This composition may be used with or Without the addition of a corrosion inhibitor.

The relative quantities of the various constituents in the engine cleaning composition of our invention may be varied within certain limits without deleteriously aifecting the beneficial effects and desirable properties of the composition. Based upon the total weight of the composition, the water content may constitute from about 0.5 per cent to about 55 per cent de pending upon the nature and amounts of detergent and solvents used. The water may be added as such or it may be admixed in part or in full with the detergent to form a pasty to liquid detergent composition which may then be blended with the solvents.

The detergent contemplated for use according to this invention is preferably a water-soluble detergent soap such as the soda soap or the potash soap of oleic acid, palmitic acid, linolenic acid, capric acid, linoleic acid, and mixtures thereof; however, an oil-soluble soap such as the oil-soluble soaps of petroleum sulfonic acids. may be employed alone or incombination with watersoluble soaps. Thesoap mayconstitute from about 0.5 per cent to about 30 per cent by weight of the total composition.

The organic solvents which wehave found to be particularly suitable in accordance with our invention are: (l) a monohydroxy benzene type solvent such as phenol, ortho, meta and paracresol, xylenols, and alkylated derivatives of phenol, ortho-, meta, and para-cresol, and xylenols, and mixtures thereof; (2) a halogenated hydrocarbon type solvent such as dichloroethylone, trichloroethylene, tetrachloroethylene, ethylene dichloride, propylen dichloride, trichloropropane, amylene dichloride, carbon tetrachloride, and chloroform; and (3) a solvent of the type ROE where R is an alkyl group, an alkoxyalkyl group, or an hydroxy alkyl group and R is an alkyl group, an alkoxyalkyl group, an hydroxy alkyl group, or hydrogen such as ethylene glycol diethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol monom ethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylbutyl mono ether of ethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propyl alcohol, butyl alcohol, and amyl alcohol. It should be understood that the specific solvents mentioned under the above three types of solvents are given by way of example and that other equivalent solvents will be apparent to those skilled in the art. The total weight of the organic solvents may constitute from about 18 per cent to about 99 per cent by weight of the total composition. 7

The relative proportions of the three types of solvents as above defined will vary depending upon the particular solvents chosen and upon the total amount of solvent mixture used. In general, we have found that the preferred ratio of the solvents from groups (1), (2), and (3) is approximately 7:3 8, respectively, although any one of the three types of solvents may be varied considerably from this ratio as long as the other two types of solvents are maintained in approximately the quoted respective ratios. In varying the amounts and the ratios of the various constituents of the present invention, it is of great importance from a commercial standpoint to produce a composition which is homogeneous. We have found that a stable, homogeneous solution will result when the constituents are varied within the above prescribed limits. In addition to the homogeneity characteristic, other characteristics and desirable properties of an efficient engine cleaning composition are: (1) it must have sufficient lubricating properties to insure safe operation of an engin during the cleansing period; (2) it must resist oxidation during long storage periods; (3) it must not corrode pistons and corrodible alloy bearings; (4) it must have a flash point high enough to permit safe use in an engine; (5) it must be able to dissolve lacquer, gum, varnish and other carbonaceous deposits; and (6) it must possess a suitable detergent action in order to wash away solid particles.

As mentioned above, a corrosion inhibitor may be used in conjunction with the engine cleaning composition of our invention. Corrosion inhibitors are particularly desirable in flushing compositions used for cleansing aluminum pistons and corrodible alloy bearings such as copper-lead, cadmium-silver, and cadmium-nickel bearings. In instances where corrosion is likely to occur, we may add an inhibitor in an amount as high as about 2 per cent by weight or more based upon the total weight of the engine cleaning composition without deleteriously aifecting the beneficial cleansing characteristics of the composition. Among the corrosion inhibitors suitable for the purpose of our invention are dibenzyl disulfide, alkyl phenyl phosphites, and sulfurized terpenes.

A tabulation of the approximate maximum and minimum amounts of constituents which may be used in accordance with our invention is as follows:

A preferred engine cleaning composition pos sessing the foregoing desirable properties in accordance with our invention is as follows:

Per cent by weight Water Potash soap 8 Organic solvents:

Mixed cresols boiling between 195 and 208 C. and having a specific gravity of 1.040 to 1.050 25 Trichloro ethylene 11 Diethylene glycol monoethyl ether Sulfurized terpenes (30 per cent sulfur) 1 The properties of the above engine cleaning composition are approximately as follows:

Gravity, degrees API 1 0.4 Viscosity, SUS at:

100 F. 44.7 210 F. 1 38.0 Color, N. P. A 3- Pour point, F -10 Flash point (D56-36), TCC, F v138 Ash, per cent 1.4

In order to determine the effectiveness of the engine cleaning compositions of the present invention for removing gum, lacquer, and carbonaceous deposits from an internal combustion engine, the following cleansing procedure may be employed. The used lubricating oil is drained from the crankcase. The engine is then torn down and examined for gum, lacquer, and other carbonaceous deposits. After determining the condition of the engine, it is reassembled, the crankcase is filled to approximately its normal capacity with an engine cleaning composition of the present invention, or, if desired, the crankcase may be filled to approximately twice its normal capacity with the engine cleaning composition. In most cases, however, it is satisfactory to use the engine cleaning composition in an amount equal to the normal crankcase capacity. The engine is then started and operated at idling speed (approximately 900 R. P. M.) with no load for a period of about minutes, more or less, at a cooling jacket temperature of about F. The crankcase temperature attained during this period depends upon the atmospheric temperature but generally is in the range of about 170 to F. At the end of the 90-minute period, the engine is stopped and the crankcase drained. The above procedure is then repeated using a light mineral lubricating oil. The latter treatment removes the engine cleaning composition held up in the engine and also aids in draining from the engine any remaining deposits which have been loosened by the engine cleaning composition. Normally, at this point the crankcase is filled to the usual level with a normal lubricating oil. However, in order to determine the cleansing quality of the engine cleaning composition, the engine may be torn down and examined.

In order to illustrate the advantageous results obtained when an engine composition of our invention is employed to remove gum, lacquer, and carbonaceous deposits from an internal combustion engine, the engine of a 1940 Chevrolet was subjected to the above-described cleansing procedure. The engine cleaning composition employed was the preferred composition set forth hereinabove. On disassembly of the engine prior to the start of the cleansing operation, the oil rin s were noted to be 100 per cent plugged with hard carbon particles bound together with a semihard oil sludge; the oil screen was caked with a semi-hard sludge about A" thick; and the crankcase oil pan contained some soft gummy sludge and was heavily lacquered. Additional lacquering was noted on the connecting rods, cylinder walls, bearings, rocker-arm assembly, and piston skirts. After the cleansing operation was completed, the oil rings were found to be 100 per cent cleaned; the oil screen was 100 per cent cleaned in the contact area; and the crankcase oil pan was clean except for a small amount of deposit in the bottom, which remained because of incomplete drainage of the crankcase. In further tests on other makes and types of engines, using a procedure similar to that described above, equally effective engine cleaning was obtained. A major proportion of the lacquer deposits was removed from the connecting rods, cylinder walls, bearings, rocker-arm assembly, and piston skirts.

In order to test the corrosion characteristics of the above-referred engine cleaning composition, two new copper-lead bearing inserts were used in No. 2 and No. 5 connecting rods in place of the original Babbitt bearings. The average Weight loss of the copper-lead bearing inserts during the above-described cleansing procedure was 0.0967 gram. When a commercially available competitive flushing composition was subjected to the same test, the average weight loss of the copper-lead bearing inserts was 0.1919 gram. The competitive flushing composition gave an increase in weight loss of 98 per cent over the composition of the present invention. The competitive flushing composition was found to be about 50 per cent as effective for the removal of gum, lacquer, and carbonaceous deposits when compared with an engine cleaning composition of the present invention.

While our invention is described above with reference to various specific examples and embodiments, it will be understood that the invention is not limited to such examples and embodiments and may be variously practiced within the scope of the claims hereinafter made.

We claim as our invention:

1. A composition for removing gum, lacquer, and carbonaceous deposits from an internal combustion engine and having suflicient lubricating properties to permit engine operation with said composition substituted for the engine lubricating oil consisting of 0.5 to 55 per cent by weight of water, 0.5 to 30 per cent by weight of a potash soap, 7 to 40 per cent by weight of mixed cresols, 3 to 17 per cent by weight of trichloroethylene, and 8 to 45 per cent by weight of diethylene glycol monoethyl ether.

2. A composition for removing gum, lacquer, and carbonaceous deposits from an internal'combustion engine and having sufficient lubricating properties to permit engine operation with said composition substituted for the engine lubricating oil consisting of 0.5 to 55 per cent by weight of water, 0.5 to 30 per cent by weight of a potash soap, 7 to 40 per cent by weight of mixed cresols, 3 to 17 per cent by weight of trichloroethylene, 8 to 45 per cent by weight of diethylene glycol monoethyl ether, and about 0.5 to 2.0 per cent by weight of sulfurized terpenes.

3. A composition for removing gum, lacquer, and carbonaceous deposits from an internal combustion engine and having sufficient lubricating properties to permit engine operation with said composition substituted for the engine lubricating oil consisting of 25 per cent by weight of water, 8 per cent by weight of a potash soap, 25 per cent by weight of mixed cresols, 11 per cent by weight of trichloroethylene, 30 per cent by weight of diethylene glycol monoethyl ether, and 1 per cent by weight of sulfurized terpenes.

4. A method of removing gum, lacquer, and carbonaceous deposits from an internal combustion engine which comprises operating said engine for a period of about minutes in the absence of lubricating oil and while the crankcase thereof is filled at least to its normal capacity with a composition consisting of a homogeneous mixture of about 0.5 to 55 per cent by weight of water, 0.5 to 30 per cent by weight of a watersoluble detergent soap and the remainder a mixture of liquid organic solvents, said mixture consisting of (1) a solvent which is a monohydroxy monocyclic phenol, (2) a chlorinated hydrocarbon, and (3) a compound selected from the group consisting of alkyl ether and hydroxyalkyl ether derivatives of ethylene glycol and diethylene glycol, the ratio of said organic solvents being about 7:3:8, respectively, and thereafter draining the crankcase.

5. A method of removing gum, lacquer, and carbonaceous deposits from an internal combustion engine which comprises operating said engine for a period of about 90 minutes in the absence of lubricating oil and while the crankcase thereof is filled at least to its normal capacity with a composition consisting of about 0.5 to 55 per cent by weight of water, 0.5 to 30 per cent by weight of a potash soap, 7 to 40 per cent by weight of mixed cresols, 3 to 17 per cent by weight of trichloroethylene, and 8 to 45 per cent by weight of diethylene glycol monoethyl ether,

and thereafter draining the crankcase.

6. A method of removing gum, lacquer, and carbonaceous deposits from an internal combustion engine which comprises operating said engine for a period of about 90 minutes in the absence of lubricating oil and while the crankcase thereof is filled at least to its normal capacity with a composition consisting of 25 per cent by weight of water, 8 per cent by weight of potash soap, 25 per cent by weight of mixed cresols, 11 per cent by weight of trichloroethylene, 30 per cent by weight of diethylene glycol monoethyl ether, and 1 per cent by weight of sulfurized terpenes, and thereafter draining the crankcase.

OLIVER L. BRANDES. CHARLES B. PATTINSON, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,836,400 Ruppert Dec. 15, 1931 2,032,174 Johnson Feb. 25, 1936 2,107,287 Curran Feb. 8, 1938 2,107,288 Curran Feb. 8, 1938 2,128,685 Yates Aug. 30, 1938 2,279,001 Matheson et al. Apr. 7, 1942 2,355,591 Flaxman Aug. 8, 1944 2,386,789 Gregg Oct. 16, 1945 2,412,633 Schwartz Dec. 17, 1946 2,556,173 Ebel June 12, 1951 

4. A METHOD OF REMOVING GUM, LACQUER, AND CARBONACEOUS DEPOSITS FROM AN INTERNAL COMBUSTION ENGINE WHICH COMPRISES OPERATING SAID ENGINE FOR A PERIOD OF ABOUT 90 MINUTES IN THE ABSENCE OF LUBRICATING OIL AND WHILE THE CRANKCASE THEREOF IS FILLED AT LEAST TO ITS NORMAL CAPACITY WITH A COMPOSITION CONSISTING OF A HOMOGENEOUS MIXTURE OF ABOUT 0.5 TO 55 PER CENT BY WEIGHT OF WATER, 0.5 TO 30 PER CENT BY WEIGHT OF A WATERSOLUBLE DETERGENT SOAP AND THE REMAINDER A MIXTURE OF LIQUID ORGANIC SOLVENTS, SAID MIXTURE CONSISTING OF (1) A SOLVENT WHICH IS A MONOHYDROXY MONOCYCLIC PHENOL, (2) A CHLORINATED HYDROCARBON, AND (3) A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALKYL ETHER AND HYDROXYALKYL ETHER DERIVATIVES OF ETHYLENE GLYCOL AND DIETHYLENE GLYCOL, THE RATIO OF SAID ORGANIC SOLVENTS BEING ABOUT 7:3:8, RESPECTIVELY, AND THEREAFTER DRAINING THE CRANKCASE. 